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Not sure if anyone still watching this thread but if there is does anyone know if I can just use a simple lock up in 3rd overdrive only for a 1994 td4.2 with same auto as mentioned .
In other words if I flick a switch in 3rd overdrive can I keep it there as long as I maintain speed .
And how do I wire it up ?
Robert
If I'm understanding your question right, yes, that would be easy. If your trans computer is the same as ours, you'd cut the wire from pin 22 and put your switch in there to feed 12 volts to the torque lock up solenoid.
You should be able to test it by sticking a pin through the wire and seeing if it gets 12 volts when you get up to about 90 km/h.
I don't understand why you'd want to manually do this though? If the trans and computer are working properly it will stay locked up itself if you stay over 90 km/h.
Also without the brake switch and park/neutral cut out you risk frying the trans by forgetting it's locked up.
Thanks for your reply , don't know if my auto is different ratio or diff gears are different but when I'm in OD and motor is cold it takes about 5-6 Klms for the change from 3rd to 4th (od) .
When in this 3rd gear torque converter is locked , revs sit at 2050rpm and speed is about 100 k , peddle response is fantastic if I plant the foot I speed up instantly but as soon as box heats up to normal revs drop to 1700 and peddle response goes .
If I can get it to stay in this third overdrive while on the blacktop it would be ideal , all other driving would just be overdrive off in 3rd but no faster than about 80 ish to keep revs down .
My third gear overdrive off ,rpm 2850 speed 95 k but overdrive on in third and cold 2050 rpm and 100 k .
Thanks for your help with this .
It's worth keeping in mind that you would use a fair bit more fuel driving in a lower gear on the straight roads.
That's the strange thing with my setup , when in OD and gearbox cold (GQ TD 4.2t) revs are only 2050 at 100 and if I put my foot down the speed increases as much as the revs so torque is locked till box is warm .
When it goes into overdrive revs drop too much and even a slight incline will slow the thing down till I put my foot down raising the rpm but converter slips causing high revs and increased heat problems .
If I could somehow fool the box into thinking it was cold all the time I would be happy but don't know if this is possible or advisable .
Sorry should have made clear 3rd gear overdrive on but locked because box not up to temp yet .
My GQ must have long legs or ratio is way out , in overdrive rpm 1700 at 100 k which is when the box heats up and it changes into fourth .
But I'm going to try the opposite to what has been done to wire 22 and simply cut it run both ends to a switch but not add power and see if that keeps it in third overdrive without changing up to fourth .
Using the pin in wire 22 I get bugger all voltage till it pops into fourth then I get 10 plus volts .
It's normal for it to take a while to warm up enough for it to lock up in 4th.
How accurate is your speedo? Ours is about 10% out (tested with GPS) so 1700 rpm is probably 100 on our speedo but only 90 in reality when the TC (Torque Converter) is locked up in 4th gear.
I suspect your cold 2050rpm is actually 4th gear (OD) before it's warm enough for the TC to lock up. Ours is more like 2500rpm with the TC manually locked in third at normal trans temps.
Cutting the wire will probably do what you want.
Thanks ripper, speedo is out by 10 Ks but I accounted for that ( must do the mod for it on this forum) will cut the wire tomorrow morning and take it for a run if it stays in third overdrive after heating up the tranny I will be happy .
Not sure if the torque lock system you and others have come up with will allow me to lock in 3rd gear od without jumping to fourth .
Don't know if my setup is different to most can only go by observation and the gear to travel on the blacktop is definately 3rd od while cool .
Throttle response is like a manual , rpm is just above 2000 at 100 Ks and like I said after 5-6 Ks it changes to fourth , revs drop to 1700 and even a small incline will slow it down .
I do realise this is different to what most seem to be doing , almost opposite in fact .
Probably doesn't help having 33s and rooftop tent and now I want to pull an 1600 kg camper trailer around as well .
Thinking more, this will do what you want BUT, you run the risk of cooking the auto if you use it too much, and you shouldn't tow your camper trailer in OD.
The factory TC lockup helps the trans run cooler as the TC generates a lot of heat when it's not locked.
We had our auto reco'd a few years ago and the auto shop said not to tow in OD. I asked about a box trailer and they were even hesitant about saying that that would be ok.
Your 33s will be reducing your revs, so 1700 at 100km/h is probably right for OD with the TC locked. We're using 31s.
Our van is about the same weight as your camper and we tow in 3rd with the TC locked. That puts us at about 2500 revs for 100km/h.
You have been so much help ripper , if cutting wire 22 works I will fit a trans oil temp gauge if oil temps are affected too much will do your version of the torque lock .
If all goes well with it I will post back to let other readers know .
Thanks again for a great thread .
No worries GQtdauto, I just know how expensive these autos can get if things go wrong with them.
Can you please start a thread intro'ing yourself here. www.nissanpatrol.com.au-Introductions
I have a question for you which is off topic for this thread.
No worries ripper , will do an intro but I'm a new old member .
I can confirm that cutting wire 22 stops gearbox from changing into fourth overdrive , I am positive that the torque converter locks in third overdrive as throttle response is excellent and there's no rpm needle bounce .
110 k at 2200 rpm ,100 k 2000 rpm using Hema gps as my speedo is out by 10 k .
First test drive didn't go so well , it was just like driving with od off , no kick down at all 90 Ks was 2400+ revs but when I stopped to connect wire 22 back up I hadn't put the plugs back in the tcu .
Will now fit a temp gauge to transmission oil .
So gearbox functions normally in every aspect it just won't go into fourth overdrive .
Great that it's doing what you want. Hope you don't have temp issues.
So do I , will get a gauge tomorrow but I can switch it on and off , thanks again for your help .
No worries.
G'day fellers. I'm a bit confused here. Gqtdauto, you talk about wanting your car to stay in 3rd gear OD. and you don't want it to go up to 4th OD. Isn't "OD" the 4th gear? So to keep it in 3rd wouldn't you just select Drive with OD off allowing the TC to do its thing automatically? I find mine TC will stay locked on the highway in 3rd by itself all day.
Hi chubba , don't ask me why or how I have no idea but as I've explained 3rd od off pulls 2600 at 90 Ks
3rd in od when cold pulls around 2050 revs at 100ks , not a mechanics ahole but I swear the torque converter locks as this gear has amazing throttle response .
Buying a temp gauge for tranny oil today which will confirm wether or not torque converter locks or not .
3rd od off when towing I find too high rpm and fuel consumption , using od the gears are changing up and down all the time and revs are also bouncing up and down .
With what I've done , in od I can lock out fourth and have about 300 rpm rev range to play with before it kicks back a gear , I'm sure it's third by counting the gear changes but it's been suggested it may be fourth unlocked .
I may be wrong but I do know the difference between an auto and a manual and in that gear it's more like a manual than an auto which is why I'm sure the torque converter locks .
Just thinking about it , it's more than likely in fourth just locked or unlocked , if someone knows what prevents the box when cold from changing up to final overdrive that will be the answer .
Interesting as I don't believe the a/t oil temp has anything 2 do with gear changes and o/dQuote:
Originally Posted by GQtdauto
Weird but true , cutting wire 22 on the TCU has the same affect of waiting for the box to heat up when cold ie it stops the box from changing into the final gear or as I suspect on mine it either turns the torque lock on or off allowing it to kick up .
Can't buy a temp gauge for tranny oil in my one horse town neither Repco or supercheap sell them or anyone else so will order from fleabay.
There is a temperature switch inside the transmission which the TCU uses to help control it. Generally the transmission will not go into 4th or O/D until it's up to temp. Lockup should occur after that at around 80km/h.
Feel like I've hijacked rippers thread so sorry ripper maybe they can move these comments?
So Chaz if I'm reading it right you're saying what I've done does lock the converter ?
Thanks rotaredom, didn't want to wreck rippers excellent torque lock thread .
I'm wondering if I'm the only one stupid enough to try this mod , although I have seen a lot of posts where people have asked basically the same question.
If wire 22 goes to the converter locking solenoid on a GQ, then cutting it will prevent the converter from locking. You need to put power onto the solenoid to lock it.Quote:
Originally Posted by GQtdauto
If you have cut the wire, try putting power onto it when you drive from second gear up and you will feel the difference. Or better still run a wire from the cig lighter socket through a switch and to the wire that you cut that goes into the transmission. Then you will be able to switch it on and off as you need, but remember never to shift into park or neutral with it switched on.
Lock up is common you can even buy kits online I believeQuote:
Originally Posted by GQtdauto
@Chaz ( good 2 see your still lurking on here ) is well know for his write up on the Lockup trans switch for his GU Nissan Patrol 3.0Di
Thanks Chaz and nissangq4.2 , will rig something up , switch I put in has extra terminals so I will just join the two sides of 22 wire one side and a positive the other side making sure I know it's off then go for a spin and activate in second gear .
As for buying a torque lock kit or making one using rippers design .
If what I'm doing won't work I'll follow ripper or buy one but I'm happy enough with the way mine works in all other ways .
That sounds like a mistake. You don't want to feed power into both of those wires, just the one that goes to the transmission, not to the tcu one.Quote:
Originally Posted by GQtdauto
Just as well I don't do anything in a hurry , thanks again ripper.
That's ok.
Tested out my version of the mod , towed like a dream revs stayed low heaps of grunt ,small medium hills all ok was actually able to overtake a car doing 93ks very easy after getting caught behind it .
Temps were up , not sure if it was this that changed the colour of the tranny oil or climbing the mountains into Wonnangatta with a ridiculous amount of water on board and fully loaded in the wrong gear , soon learnt to use first gear on the vertical stuff .
Stopping the TC from locking like you are should make it run hotter and may burn the ATF.Quote:
Originally Posted by GQtdauto
Yeah I'm converting to the lockup mod and won't use the one I did again .
It's a pity because those sorts of revs are ideal.
Need someone to make a 2 speed diff for when we're towing.